Differential equations of applied mathematics / G. F. D. Duff, D. Naylor. Duff, G. F. D. Naylor, Derek. jt. aut. Differential equations, Partial. Mathematical physics. QA377 .D78 517.38 DUD Includes index. Bibliography: p. 417-418. New York : Wiley, 1966. 1966. 1966 Text xi, 423 p. : eng